DAY 2

Question 1

In triangular coordinates, the ternary composition point falls __________ of the triangle.
a. in the corners
c. inside
b. on the sides

Answer 1

c. inside

Question 2

Sides of equilateral-triangular co-ordinates (on which ternary liquid system is plotted) represent
a. a pure component.
c. a ternary mixture.
b. a binary mixture.

Answer 2

b. a binary mixture.

Question 3

columns are used for liquid dispersion in a continuous gas phase.
a. sieve plate
b. packed
c. bubble cap
d. pulse

Answer 3

b. packed

Question 4

__________ extractor uses centrifugal force for separating the two phases.
a. Treybal
c. Schiebel
b. Podbielniak

Answer 4

b. Podbielniak

Question 5

__________ functions are exemplified by heat and work.
a. path
c. point
b. state
d. none of these

Answer 5

a. path

Question 6

__________ is the most used ‘filter aid’.
a. Diatomaceous earth
c. Fuller’s earth
b. Vermiculite
d. Semi-plastic clay

Answer 6

a. Diatomaceous earth

Question 7

__________ is the temperature at which a gas-vapor mixture becomes saturated, when cooled at constant total pressure out of contact with a liquid.
a. Dew point
c. Bubble point
b. Dry bulb temperature
d. Wet bulb temperature

Answer 7

a. Dew point

Question 8

__________is used as an ‘entrainer’ for the separation of acetic acid-water mixture by distillation.
a. Furfural
b. Butyl acetate
c. Benzol
d. Hexane

Answer 8

b. Butyl acetate

Question 9

200 mesh screen means 200 openings per
a. cm2
c. cm
b. inch
d. inch2

Answer 9

b. inch

Question 10

A __________ evaporator employs an annular down take.
a. basket type
c. horizontal
b. long tube vertical
d. none of these

Answer 10

a. basket type

Question 11

A 50 % by weight benzene – toluene mixture is fed to a column at 180 0F and 1 atm. The condition of the feed is called
a. saturated liquid
c. saturated vapor
b. sub cooled liquid

Answer 11

b. sub cooled liquid

Question 12

A ball mill 1.2 m in diameter is being run at 0.8 Hz. It is found that the mill is not working satisfactorily. Would you suggest any modification in the condition of operation?
a. The speed of rotation should be doubled
b. The speed of rotation should be halved
c. The speed of rotation should be tripled
d. No, the speed of rotation should be the same

Answer 12

b. The speed of rotation should be halved

Question 13

A batch reactor is characterized by
a. constant residence time
b. the variation in extent of reaction and properties of the reaction mixture with time
c. variation in reactor volume
d. very low conversion

Answer 13

b. the variation in extent of reaction and properties of the reaction mixture with time

Question 14

A batch reactor is suitable for
a. liquid phase reactions
b. large scale gaseous phase reactions.
c. obtaining uniform polymerisation products in highly exothermic reactions.
d. achieving cent percent conversion of reactants into products.

Answer 14

a. liquid phase reactions

Question 15

A catalyst
a. lowers the activation energy of reacting molecules.
b. can not be recovered chemically unchanged at the end of a chemical reaction.
c. is capable of reacting with any one of the reactants.
d. initiates a reaction.

Answer 15

a. lowers the activation energy of reacting molecules.

Question 16

A certain reaction has a specific rate constant of 10 L/mol-min. The order of the reaction is
a. ½
c. 1
b. 0
d. 2

Answer 16

d. 2

Question 17

A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system
a. its internal energy (U) decreases and its entropy (S) increases.
b. U and S both decreases
c. U decreases but S is constant.
d. U is constant but S decreases.

Answer 17

b. U and S both decreases

Question 18

A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because
a. total heat transfer area of all the effects is less than that in a single effect evaporator system.
b. total amount of vapor produced per kg of feed steam in a multiple effect system is much higher than in a single effect.
c. boiling point elevation in a single effect system is much higher than that in any effect in a multi effect system.
d. heat transfer coefficient in a single effect is much lower than that in any effect in a multi-effect system.

Answer 18

b. total amount of vapor produced per kg of feed steam in a multiple effect system is much higher than in a single effect.

Question 19

A dimensionless number that represents the ratio of the molecular momentum diffusion to the molecular mass diffusivity
a. Sherwood Number
c. Schmidt Number
b. Reynolds Number
d. Rayleigh Number

Answer 19

c. Schmidt Number

Question 20

A filter press is
a. a batch filter.
b. not suitable, if the liquid is the main product.
c. having prohibitively high maintenance cost.
d. not suitable for wide range of materials under varying operating conditions of cake thickness and pressure.

Answer 20

a. a batch filter.

Question 21

A first order irreversible reaction, A → B is carried out separately in aconstant volume as well as in a variable volume reactor for a particular period.It signifies that in the two reactors
a. both conversion as well as concentration are same
b. conversion in both will be the same but concentrations will be different
c. both the conversion as well as concentrations will be different
d. none of these.

Answer 21

b. conversion in both will be the same but concentrations will be different

Question 22

A gravity decanter is meant for the separation of two __________ density.
a. immiscible liquids of different
b. miscible liquids of different
c. immiscible liquids of same
d. miscible liquids of same

Answer 22

a. immiscible liquids of different

Question 23

A minimum boiling azeotrope is exemplified by
a. toluene-benzene
b. acetone-carbon disulfide
c. water-isobutyl alcohol

Answer 23

b. acetone-carbon disulfide

Question 24

A plug-flow reactor is characterized by
a. high capacity
b. presence of axial mixing
c. presence of lateral mixing
d. constant composition and temperature of reaction mixture

Answer 24

c. presence of lateral mixing

Question 25

A process stream of dilute aqueous solution flowing at the rate of 10 kg-s-1 is to be heated. Steam condensate at 95°C is available for heating purpose, also at a rate of 10 kg-s-1. A 1 - 1 shell and tube heat exchanger is available. The best arrangement is a. counter flow with process stream on shell side. b. parallel flow with process stream on shell side. c. counter flow with process stream on tube side. d. parallel flow with process stream on tube side.

Question 26

A refrigeration cycle is a reversed heat engine. Which of the following has the maximum value of the coefficient of performance (COP) for a given refrigeration effect? a. Vapor compression cycle using expansion valve. b. Air refrigeration cycle. c. Vapor compression cycle using expansion engine. d. Carnot refrigeration cycle.

Answer 26

d. Carnot refrigeration cycle.

Question 27

A solid is transformed into vapor without going through the liquid phase at a. below triple point c. triple point b. boiling point d. always

Answer 27

c. triple point

Question 28

A solid material shows case hardening properties while drying. Which of the following should be controlled to control the drying process? a. Flow rate of inlet air c. Relative humidity of outlet air b. Humidity of inlet air d. Temperature of the solid

Answer 28

d. Temperature of the solid

Question 29

A space velocity of 5/hour means that a. five reactor volumes of feed (at specified conditions) are being fed into the reactor per hour b. after five hours, reactor is being filled with the feed c. percent conversion can be achieved in at least 5 hours d. a fixed conversion of a given batch of feed takes 5 hours

Answer 29

a. five reactor volumes of feed (at specified conditions) are being fed into the reactor per hour

Question 30

A space-time of 3 hours for a flow reactor means that a. the time required to process one reactor volume of feed (measured at specified conditions) is 3 hour b. three reactor volumes of feed can be processed every hour c. it takes three hours to dump the entire volume of the reaction with feed d. conversion is per cent after three hour

Answer 30

a. the time required to process one reactor volume of feed (measured at specified conditions) is 3 hour

Question 31

Acetic acid will be most economically separated from a dilute solution of acetic acid in water by a. solvent extraction c. continuous distillation b. evaporation

Answer 31

a. solvent extraction

Question 32

Air initially at 101. 3 kPa and 40°C and with a relative humidity of 50%, is cooled at constant pressure to 30°C. The cooled air has a a. higher dew point. b. higher absolute (specific) humidity. c. higher relative humidity d. higher wet bulb temperature.

Answer 32

c. higher relative humidity

Question 33

Air is best heated with steam in a heat exchanger of a. double pipe type with fin on steam side b. shell and tube type c. double pipe type with fin on air side d. plate type

Answer 33

c. double pipe type with fin on air side

Question 34

Ammonia (A) being absorbed from air (B) into water is an example of a. steady-state equimolal diffusion b. stead-state unicomponent c. steady-state multicomponent diffusion d. unsteady-state equimolal diffusion

Answer 34

b. stead-state unicomponent

Question 35

An aqueous solution of methanol is to be distilled in a tray column. High pressure steam is available as a source of heat. For a given reflux ratio and overhead composition, two options are being explored; (i) a reboiler is used and (ii) no reboiler is used but steam is fed directly to the bottom of the column. As compared to option (i), in option (ii) a. composition of the residue remains unchanged b. more number of trays are required but the residue composition remains unchanged. c. less number of trays are required. d. more number of trays are required and the residue composition is more dilute in methanol.

Answer 35

c. less number of trays are required.

Question 36

An example of autothermal reactor operation is a. ammonia synthesis b. benzene oxidation c. ethylene oxidation d. sulfur dioxide oxidation

Answer 36

c. ethylene oxidation

Question 37

An example of elutioh is a. separation of sugar from sugar beet by hot water. b. separation of uranium oxide from its ore by H2SO4 in a Pachuca tank. c. recovery of vegetable oils from seeds. d. dissolution of tannin out of tree barks by water

Answer 37

b. separation of uranium oxide from its ore by H2SO4 in a Pachuca tank.

Question 38

An ideal surface that absorbs all incident radiation, regardless of the wavelengths and direction and is also considered to be a perfect emitter is referred to as a a. gray body c. black body b. black hole d. pin hole

Answer 38

c. black body

Question 39

Antibiotics are best handled in a a. Podbielniak extractor c. rotating disc contactor b. sieve tray contractor

Answer 39

a. Podbielniak extractor

Question 40

Arrange the following size reduction equipment in the decreasing order of the average particle size produced by each of them. a. Jaw crusher, Ball mill, Fluid energy mill b. Ball mill, Jaw crusher, Fluid energy mill c. Fluid energy mill, Jaw crusher, Ball mill d. Fluid energy mill, Ball mill, Jaw crusher

Answer 40

a. Jaw crusher, Ball mill, Fluid energy mill

Question 41

As particle size is reduced a. screening becomes progressively more difficult b. screening becomes progressively easier c. capacity and effectiveness of the screen is increased d. none of these

Answer 41

a. screening becomes progressively more difficult

Question 42

As the product becomes finer, the energy required for grinding a. decreases b. is same as for coarser grinding c. increases d. is 1.5 times than for coarser grinding

Answer 42

c. increases

Question 43

As the reflux ratio decreases, the a. separation becomes more efficient. b. number of plates increases. c. column diameter increases.

Answer 43

b. number of plates increases.

Question 44

At minimum reflux ratio for a given separation a. number of plates is zero. b. number of plates is infinity. c. minimum number of the theoretical plates is required.

Answer 44

b. number of plates is infinity.

Question 45

At what percentage (by volume) of alcohol composition, it forms an azeotrope with water? a. 90 c. 91.5 b. 95

Answer 45

b. 95

Question 46

Azeotropic distillation is employed to separate a. constant boiling mixture b. high boiling mixture c. mixture with very high relative volatility

Answer 46

a. constant boiling mixture

Question 47

Back-trapping in a distillation column a. increases tray efficiency. b. decreases tray efficiency. c. reduces pressure drop.

Answer 47

b. decreases tray efficiency.

Question 48

Ball mills and tube mills with flint or porcelain balls are used for size reduction of a. limestone b. asbestos c. rubber d. non-metallic ores

Answer 48

d. non-metallic ores

Question 49

Black liquor generated during paper manufacture is concentrated in a a. single effect evaporator. b. single effect evaporator followed by a crystallizer. c. multiple effect evaporator. d. multiple effect evaporators followed by a crystallizer.

Answer 49

c. multiple effect evaporator.

Question 50

Boiling point diagram is a. not affected by pressure. b. affected by pressure. c. a plot of temperature vs. liquid composition.

Answer 50

b. affected by pressure.

Question 51

Boiling point elevation for a strong and concentrated solution is found by Duhring's rule, which states that at the same pressure, the boiling point of a solution is a linear function of the __________ of pure water. a. boiling point c. dynamic viscosity b. kinematic viscosity d. density

Answer 51

a. boiling point

Question 52

Boiling point of a solution according to Duhring's rule is a linear function of the __________ of water. a. boiling point (at the same pressure) b. viscosity c. density d. thermal conductivity

Answer 52

a. boiling point (at the same pressure)

Question 53

Bollman extractor a. is a static bed leaching equipment. c. is a centrifugal extractor. b. is used for extraction of oil from oil seed.

Answer 53

b. is used for extraction of oil from oil seed.

Question 54

Buoyant force a. for non-symmetrical bodies is not vertical b. depends on the depth of the submergence of the floating body c. depends on the weight of the floating body d. none of these

Answer 54

c. depends on the weight of the floating body

Question 55

Can the efficiency of a plate in the distillation tower be greater than 100%? a. Yes b. Normally not; but is possible if infinite number of plates are put. c. Never

Answer 55

c. Never

Question 56

Carbon black is pulverized in a a. hammer crusher c. ball mill b. roll crusher d. gyratory crusher

Answer 56

c. ball mill

Question 57

Channeling in a packed tower results from a. high pressure drop b. non-uniformity of packing c. maldistribution of liquid d. both b and c

Answer 57

c. maldistribution of liquid

Question 58

Coefficient of Performance (COP) of a refrigerator is the ratio of the a. work required to refrigeration obtained. b. refrigeration obtained to the work required. c. lower to higher temperature. d. higher to lower temperature.

Answer 58

b. refrigeration obtained to the work required.

Question 59

Compressibility factor of a gas is a. not a function of pressure b. not a function of its nature c. not a function of its temperature d. unity, if it follows PV = nRT

Answer 59

d. unity, if it follows PV = nRT

Question 60

Condensation of a vapor-gas mixture just begins, when (where, p = partial pressure of the vapor P = vapor pressure of the liquid) a. p = P c. p >>P b. p < P d. p << P

Answer 60

a. p = P

Question 61

Cork is a good insulator because it has a. free electrons b. atoms colliding frequency c. low density d. porous body

Answer 61

d. porous body

Question 62

Cp – Cv = R is valid for a. ideal gases b. all gases c. gases at very high pressure d. gases at a very low temperature

Answer 62

a. ideal gases

Question 63

Crushing efficiency is the ratio of the a. surface energy created by crushing to the energy absorbed by the solid. b. energy absorbed by the solid to that fed to the machine. c. energy fed to the machine to the surface energy created by crushing. d. energy absorbed by the solid to the surface energy created by crushing.

Answer 63

a. surface energy created by crushing to the energy absorbed by the solid.

Question 64

Crystallization of solids from a homogeneous solution is a/an __________ process. a. exothermic c. mildly endothermic b. highly endothermic d. none of these

Answer 64

a. exothermic

Question 65

Cv is given by a. (∂U/ ∂T)v c. (∂U/∂V)T b. (∂U/∂P)v d. (∂V/ ∂T)P

Answer 65

a. (∂U/ ∂T)v

Question 66

Degree of freedom at triple point will be a. 0 c. 1 b. 2 d. 3

Answer 66

a. 0

Question 67

Design calculation for multiple component distillation is done by a. Ponchon-Savarit method b. Mccabe-Thiele method c. enthalpy concentration method

Answer 67

d. tray to tray calculations

Question 68

Desulfurization of petrol is done in a a. Bollman extractor b. rotating disc extractor c. packed extraction column

Answer 68

b. rotating disc extractor

Question 69

Drag is defined as the force exerted by the a. fluid on the solid in a direction opposite to flow b. the fluid on the solid in the direction of flow c. the solid on the fluid d. none of these

Answer 69

b. the fluid on the solid in the direction of flow

Question 70

Drying operation under vacuum is carried out to a. dry those materials which have very high unbound moisture content. b. reduce drying temperature. c. increase drying temperature. d. dry materials having high bound moisture content.

Answer 70

b. reduce drying temperature.

Question 71

During adiabatic expansion of gas a. pressure remains constant b. pressure is increased c. temperature remains constant d. none of these

Answer 71

d. none of these

Question 72

During washing of filter at the end of constant pressure filtration, the rate of washing equals the rate of filtration a. at time zero. b. at the end of filtration. c. when half the filtrate has been obtained. d. at the end of filtration but decreases with time subsequently.

Answer 72

b. at the end of filtration.

Question 73

Energy requirement (per unit mass of material crushed/ground) is highest for a. jaw crusher c. rod mill b. ball mill d. fluid energy mill

Answer 73

d. fluid energy mill

Question 74

Entrainer used in azeotropic distillation should a. form a new azeotrope of low relative volatility with one of the constituents of the mixture. b. have high latent heat of vaporization. c. have high viscosity to provide high tray efficiency. d. form a low boiling azeotrope with one of the constituents of the mixture.

Answer 74

d. form a low boiling azeotrope with one of the constituents of the mixture.

Question 75

Entropy is a measure of the __________ of a system. a. disorder c. temperature changes only b. orderly behavior d. none of these

Answer 75

a. disorder

Question 76

Equation which relates pressure, volume, and temperature of a gas is called a. Equation of state c. Gibbs Duhem equation b. ideal gas equation d. all of these

Answer 76

a. Equation of state

Question 77

Evaporation of 1kg of water from a solution in a single effect evaporator requires about __________ kg of steam. a. 0.4 - 0.6 c. 1 - 1.3 b. 1.8 - 2 d. 2 - 2.4

Answer 77

c. 1 - 1.3

Question 78

Feed size of ≥ 25 cms can be accepted by a. ball mill c. rod mill b. fluid energy mill d. jaw crusher

Answer 78

d. jaw crusher

Question 79

Fenske equation determines the a. maximum number of ideal plates. b. height of the distillation column. c. minimum number of theoretical plates.

Answer 79

c. minimum number of theoretical plates.

Question 80

Fenske's equation for determining the minimum number of theoretical stages in distillation column holds good, when the a. relative volatility is reasonably constant. b. mixture (to be separated) shows negative deviation from ideality. c. mixture (to be separated) shows positive deviation from ideality.

Answer 80

a. relative volatility is reasonably constant.

Question 81

Filter aid is used a. to increase the rate of filtration b. to decrease the pressure drop c. to increase the porosity of the cake d. as a support base for the septum

Answer 81

c. to increase the porosity of the cake

Question 82

Filtration of water in a paper mill is done by a/an __________ filter. a. open sand c. plate and frame b. vacuum leaf d. sparkler

Answer 82

a. open sand

Question 83

Filtration operation carried out by continuous increase of the inlet pressure of slurry, is called the __________ filtration. a. constant rate c. varying pressure b. varying rate d. constant pressure

Answer 83

d. constant pressure

Question 84

Flash distillation is suitable for separating the constituents of a binary system, which a. form minimum boiling azeotrope. b. have very wide boiling points. c. have very close boiling points.

Answer 84

b. have very wide boiling points.

Question 85

Flights in a rotary dryer are provided to a. lift and shower the solids thus exposing it thoroughly to the drying action of the gas. b. reduce the residence time of solid. c. increase the residence time of the solid. d. none of these.

Answer 85

a. lift and shower the solids thus exposing it thoroughly to the drying action of the gas.

Question 86

Flooding in a column results due to a. high pressure drop b. low pressure drop c. low velocity of the liquid d. high temperature

Answer 86

a. high pressure drop

Question 87

Flooding results in a. high tray efficiency b. low tray efficiency c. high gas velocity d. good contact between the fluids

Answer 87

b. low tray efficiency

Question 88

Flow of filtrate through the cake in a plate and frame filter press is best described by the __________ equation. a. Kozney-Karman b. Fanning's c. Hagen-Poiseulle's d. Kremser

Answer 88

a. Kozney-Karman

Question 89

For a __________ order reaction, the units of rate constant and rate of reaction are the same. a. zero c. first b. second d. fractional

Answer 89

a. zero

Question 90

For a binary mixture distillation process, the degree of freedom is 2. However, if the pressure is fixed in this process, the number of independent variables in this process will be a. 1 b. 3 c. 2 d. 0

Answer 90

a. 1

Question 91

For a binary mixture with low relative volatility, continuous rectification to get pure products will require a. low reflux ratio b. small cross-section column c. high reflux ratio d. less number of trays

Answer 91

c. high reflux ratio

Question 92

For a constant pressure reversible process, the enthalpy (∆H) change of the system is a. C vdT c. CpdT b. ∫CpdT d. ∫CvdT

Answer 92

b. ∫CpdT

Question 93

For a cyclic process, a fixed ratio between heat and work a. always exists c. may exist b. never exists d. is difficult to predict

Answer 93

a. always exists

Question 94

For a gas phase diffusion, unicomponent diffusion through a gas- liquid interface will likely to occur if a. one component is soluble and the other is not b. both components are soluble in the solvent c. both components are insoluble in the solvent d. none of these

Answer 94

a. one component is soluble and the other is not

Question 95

For an ideal fluid flow, the Reynolds number is a. 2100 b. 100 c. zero d. infinity

Answer 95

d. infinity

Question 96

For an identical conversion and throughput, which of the reactors will have a larger volume if the reaction is second order? a. backmix reactor b. either of the two c. cannot be determined d. plug flow reactor

Answer 96

a. backmix reactor

Question 97

For an isothermal process the internal energy of a gas a. increases b. decreases c. remains unchanged d. data insufficient can’t be predicted

Answer 97

c. remains unchanged

Question 98

For ethanol-water system, the lowering of distillate quality from 95% to 92% will cause __________ plate requirement. a. None of these b. no change in theoretical c. marginal decrease in the number of d. major decrease in the number of

Answer 98

c. marginal decrease in the number of

Question 99

For evaporation of viscous solution in a multiple effect evaporator, the preferred feeding scheme is a. forward c. backward b. parallel d. none of these

Answer 99

c. backward

Question 100

For laminar flow of filtrate through the cake deposited on septum, which of the following will be valid? a. Kozeney-Karman equation b. Leva's equation c. Blake-Plummer equation d. none of these

Answer 100

a. Kozeney-Karman equation

Question 101

For pipes that must be broken at intervals for maintenance, the connector used should be a/an a. union c. tee b. reducer d. elbow

Answer 101

a. union

Question 102

For removal of very small amounts of precipitate from large volume of water, the most suitable filter is the __________ filter. a. plate and frame c. shell and leaf b. sand d. rotary vacuum

Answer 102

b. sand

Question 103

For separation of sugar solution from settled out mud, we use a ______ filter. a. sparkler c. plate and frame b. centrifugal d. rotary drum vacuum

Answer 103

b. centrifugal

Question 104

For sizing of fine materials, the most suitable equipment is a a. trommel c. grizzly b. shaking screen d. vibrating screen

Answer 104

d. vibrating screen

Question 105

For the laminar flow of a fluid in a circular pipe of radius R, the Hagen-Poiseuille equation predict the volumetric flowrate to be proportional to a. R^0 b. R^4 c. R d. R^2

Answer 105

b. R^4

Question 106

For the preliminary breaking of hard rock, we use a. gyratory crusher c. tube mill b. ball mill d. quirrel-cage disintegrator

Answer 106

a. gyratory crusher

Question 107

For the same feed, feed quality and separation (in a distillation column), with the increase of total pressure, the number of ideal plates will a. increase b. decrease c. remains same

Answer 107

a. increase

Question 108

For the same heat transfer area and the terminal conditions, the ratio of the capacities of a single effect evaporator to a triple effect evaporator is a. 3 c. 0.33 b. 1 d. 1.33

Answer 108

b. 1

Question 109

For turbulent mass transfer in pipes, the Sherwood number depends upon the Reynolds number (Re) as a. Re^0.33 c. Re^0.53 b. Re^0.83 d. Re

Answer 109

b. Re^0.83

Question 110

For water-ethanol system, the minimum reflux ratio a. is computed from the slope of the upper operating line that is tangent to the equilibrium curve. b. cannot be computed c. is the optimum reflux ratio. d. is computed from the intercept of the operating line.

Answer 110

a. is computed from the slope of the upper operating line that is tangent to the equilibrium curve.

Question 111

Forced circulation evaporators are useful for the concentration of viscous, salting and scale forming liquors. Which of the following is a forced circulation evaporator? a. Long vertical evaporator b. Horizontal tube evaporator c. Agitated film evaporator d. Calandria vertical tube evaporator

Answer 111

c. Agitated film evaporator

Question 112

Forces acting on a particle settling in fluid are a. gravitational and buoyant forces b. centrifugal and drag forces c. gravitational or centrifugal, buoyant and drag forces d. external, drag and viscous forces

Answer 112

c. gravitational or centrifugal, buoyant and drag forces

Question 113

Fractional conversion __________ for an exothermic reversible chemical reaction, when the temperature is maximum. a. increases c. remains unchanged b. decreases d. unpredictable from the data

Answer 113

b. decreases

Question 114

Free flowing granular materials can be best dried in a __________ drier. a. rotary c. cylinder b. drum d. freeze

Answer 114

a. rotary

Question 115

From among the following, choose one which is not an exothermic process. a. Ammonia synthesis b. Catalytic cracking c. Oxidation of sulfur d. Methanol synthesis

Answer 115

b. Catalytic cracking

Question 116

From PVn = C, the process is isochoric if n equals a. 0 c. 1 b. δ d. ∞

Answer 116

d. ∞

Question 117

From PVn = C, when n = 0, the process is a. isochoric c. polytropic b. isothermal d. isobaric

Answer 117

d. isobaric

Question 118

Fundamental principle of refrigeration is based on the __________ law of thermodynamics. a. zeroth c. first b. second d. third

Answer 118

b. second

Question 119

Generation of heat by friction is an example of a/an __________ change. a. isothermal c. irreversible b. adiabatic d. reversible

Answer 119

c. irreversible

Question 120

Gyratory crushers compared to the reciprocating jaw crushers a. have greater capacity per unit of discharge area. b. crush intermittently. c. are less suitable for coarse materials. d. have less steady power consumption.

Answer 120

a. have greater capacity per unit of discharge area.

Question 121

Half-life period of a chemical reaction is a. the time required to reduce the concentration of the reacting substance to half its initial value b. half of the space time of the reaction c. half of the residence time of the reaction d. none of these

Answer 121

a. the time required to reduce the concentration of the reacting substance to half its initial value

Question 122

Heat sensitive materials can be concentrated in an evaporator employing a. vacuum c. high pressure b. high residence time d. none of these

Answer 122

a. vacuum

Question 123

Heat sensitive materials like certain pharmaceuticals and food stuff can be dried a. in indirect tray dryer c. in spray dryer b. by freeze drying d. festoon dryer

Answer 123

b. by freeze drying

Question 124

Heat transfer in turbulent flow may be described by an empirical equation correlating a. Nusselt, Peclet, Prandtl numbers b. Nusselt, Prandtl, Stanton numbers c. Nusselt, Prandtl, Reynolds numbers d. Nusselt, Graetz, Schimdt numbers

Answer 124

c. Nusselt, Prandtl, Reynolds numbers

Question 125

Heat transfer occurs by natural convection because change in temperature causes differences in a. viscosity c. thermal conductivity b. density d. heat capacity

Answer 125

b. density

Question 126

Heating of water under atmospheric pressure is an __________ process. a. isochoric c. isobaric b. adiabatic d. isothermal

Answer 126

c. isobaric

Question 127

High pressure at the bottom of a distillation tower handling heat sensitive materials results in a. thermal decomposition of bottoms. b. erosion of the tower. c. increased relative volatility. d. very efficient operation.

Answer 127

a. thermal decomposition of bottoms.

Question 128

High specific speed of a pump implies that, it is a/an          pump. a. axial flow b. centrifugal c. none of these d. mixed flow

Answer 128

a. axial flow

Question 129

How many intensive variables must be specified to fully describe a system containing mixture of water, liquid benzene and nitrogen. a. 1 b. 3 c. 2 d. 0

Answer 129

c. 2

Question 130

Hydrogenation of oil is carried out in a/an __________ in Vanaspati manufacturing plant. a. agitated vessel b. sieve tray column c. packed tower d. bubble cap column

Answer 130

a. agitated vessel

Question 131

Ideal refrigeration cycle is a. dependent on the refrigerant's properties b. same as reverse Carnot cycle. c. the least efficient of all refrigeration processes. d. same as carnot cycle

Answer 131

b. same as reverse Carnot cycle.

Question 132

If “n” is the order of reaction, then unit of rate constant is a. 1 / (time) (concentration)n-1 b. (time)-1(concentration)n-1 c. (time)n-1 (concentration) d. none of these

Answer 132

a. 1 / (time) (concentration)n-1

Question 133

If a force greater than that of gravity is used to separate solids & fluids of different densities, the process is termed as the a. sedimentation c. flocculation b. dispersion d. centrifugation

Answer 133

d. centrifugation

Question 134

If a man touches two metals which were kept together at room temperature, why would one metal feel colder than the other a. one has a high heat transfer coefficient b. one has a high thermal conductivity c. one has a lower temperature d. one has a higher heat capacity

Answer 134

b. one has a high thermal conductivity

Question 135

If the radius of a basket centrifuge is halved and the rpm is doubled, then a. linear speed of the basket is doubled b. linear speed of the basket is halved c. centrifugal force is doubled d. capacity of centrifuge is increased

Answer 135

c. centrifugal force is doubled

Question 136

If the rate of reaction independent of the concentration of the reactants, the reaction is said to be? a. first order c. second order b. third order d. zero order

Answer 136

d. zero order

Question 137

If the reaction, 2 A → C is second order, which of the following plots will give a straight line? a. log CA vs time c. log CA vs reciprocal time b. CA vs time d. 1/CA vs time

Answer 137

d. 1/CA vs time

Question 138

If the solubilities of different components (in a liquid-liquid extraction system) increase with rise in temperature, then the temperature above which they dissolve completely is known as the critical solution temperature (CST or consolute temperature). If solubilities increase with decrease in temperature, then CST is the temperature below which they dissolve completely. If a binary system has no critical solution temperature, it implies that a. the system comprises of miscible liquids b. the system comprises of an azeotrope. c. on heating, a vapor phase will appear ; while on cooling, a solid phase will appear. d. the system comprises of partially mis-cible liquids. the system comprises of partially miscible liquids.

Answer 138

c. on heating, a vapor phase will appear ; while on cooling, a solid phase will appear.

Question 139

If the time required for half change is inversely proportional to the square of initial concentration and the velocity depends on the units in which the concentration term is expressed, then the order of reaction is a. 0 b. 2 c. 1 d. 3

Answer 139

d. 3

Question 140

If the time required to change the concentration of reactant to half its original value is independent of the initial concentration, the order of reaction is a. zero c. one b. two d. three

Answer 140

c. one

Question 141

If Rm is the minimum reflux ratio, the optimum reflux ratio may be around __________ Rm. a. 3 to 4 b. 5 c. 2.5 to 3 d. 1.2 to 1.5

Answer 141

d. 1.2 to 1.5

Question 142

In a backward feed multiple effect evaporator a. feed is introduced in the first effect. b. feed flows from low pressure to high pressure. c. no pumps are required between successive effects. d. none of these.

Answer 142

b. feed flows from low pressure to high pressure.

Question 143

In a batch distillation, the boiling point of the distillate product compared to the residue is a. the same c. lower b. higher

Answer 143

c. lower

Question 144

In a counter-current extractor, as the axial mixing increases, the extraction efficiency a. increases c. remains unchanged b. decreases

Answer 144

b. decreases

Question 145

In a counter-current liquid extractor a. both liquids flow at fixed rate. b. both liquids can have any desired flow rate. c. only one of the liquids may be pumped at any desired rate.

Answer 145

c. only one of the liquids may be pumped at any desired rate.

Question 146

In a distillation column, with increase in the reflux ratio, the heat removed in the cooler a. increases. b. decreases. c. remains unaffected.

Answer 146

a. increases.

Question 147

In a distilling column, the highest pressure will be at a. the top b. the bottom c. the feed plate

Answer 147

b. the bottom

Question 148

In a forward feed multiple effect, the pressure build up will be a. least at the inlet of the first effect. b. least at the outlet of the last effect. c. highest at the inlet of the last effect. d. highest at the outlet of the last effect.

Answer 148

b. least at the outlet of the last effect.

Question 149

In a gas absorption tower, mass transfer occurs primarily a. from the liquid phase to the gas phase b. from the liquid phase to the packing c. from the gas phase to the liquid phase d. from the gas phase to the packing

Answer 149

c. from the gas phase to the liquid phase

Question 150

In a size reduction crushing operation, feed size is 100 to 300 mm. while the product size is 10 to 50 mm. This is a case of the __________ crushing. a. primary c. secondary b. fine d. ultrafine

Answer 150

c. secondary

Question 151

In a size reduction crushing operation, feed size is 300 to 1500 mm while the product size is 100 to 300 mm. This is a case of the __________ crushing. a. secondary c. fine b. primary d. ultrafine

Answer 151

b. primary

Question 152

In a size reduction crushing operation, the feed size is 10 to 50 mm, while the product size is 2 to 10 mm. This is a case of __________ crushing. a. primary c. secondary b. fine d. ultrafine

Answer 152

b. fine

Question 153

In an operating distillation column, the a. vapors and liquids are at their dew point and bubble point respectively b. driving force for the vapor flow is the pressure drop, as the pressure decreases gradually from the bottom to the top of the column. c. driving force for the liquid flow is its specific weight. d. highest temperature is encountered at the top of the column

Answer 153

b. driving force for the vapor flow is the pressure drop, as the pressure decreases gradually from the bottom to the top of the column.

Question 154

In batch distillation with constant reflux, overhead product composition __________ with time. a. increases b. decreases c. does not vary

Answer 154

b. decreases

Question 155

In case of a plate and frame filter press, filtrate flow through the cake follows __________ flow. a. plug c. turbulent b. laminar d. none of these

Answer 155

b. laminar

Question 156

In case of an ideal solution, the total vapor pressure varies __________ with the composition expressed as mole fraction, a. linearly b. none of these c. exponentially d. inversely

Answer 156

a. linearly

Question 157

In case of evaporators, liquid entrainment results primarily due to a. high vacuum in the evaporator. b. high evaporation rate. c. foaming of the solution. d. high heat transfer rate.

Answer 157

c. foaming of the solution.

Question 158

In case of liquid-liquid binary diffusion, diffusivity of one constituent into another is not dependent on the a. temperature and pressure b. concentration c. none of these d. nature of constituents

Answer 158

c. none of these

Question 159

In case of steam distillation, the steam leaving the liquid is not completely saturated with distillate vapor, because a. temperature is less. b. saturated steam is used for steam distillation. c. mixing of steam with the material being vaporised is not so intimate as to result in equilibrium condition. d. total pressure is less.

Answer 159

c. mixing of steam with the material being vaporised is not so intimate as to result in equilibrium condition.

Question 160

In case of vertical tube evaporator, with increase in liquor level, the overall heat transfer coefficient a. increases b. decreases c. is not affected d. may increase or decrease; depends on the feed

Answer 160

b. decreases

Question 161

In constant pressure filtration, a. resistance decreases with time b. rate of filtration is constant c. rate of filtration increases with time d. rate of filtration decreases with time

Answer 161

d. rate of filtration decreases with time

Question 162

In continuous filtration (at a constant pressure drop), filtrate flow rate varies inversely as the a. square root of the velocity. b. square of the viscosity. c. filtration time only. d. washing time only.

Answer 162

a. square root of the velocity.

Question 163

In distillation columns, the number of bubble caps per tray primarily depends upon the a. allowable gas velocity b. feed composition. c. allowable liquid velocity. d. allowable gas and liquid velocities.

Answer 163

d. allowable gas and liquid velocities.

Question 164

In distillation where q is defined as the moles of liquid flow in the stripping section per mole of feed introduced, for saturated liquid feed a. q > 1 c. q < 1 b. q = 1

Answer 164

b. q = 1

Question 165

In distillation, overhead product contains a. only one component b. two components c. any number of components

Answer 165

c. any number of components

Question 166

In extractive distillation, solvent is a. added to alter the relative volatility of the mixture. b. of high volatility. c. present in overhead stream.

Answer 166

a. added to alter the relative volatility of the mixture.

Question 167

In filtration, the use of 'filter aid' helps in a. reducing the filtration pressure. b. accelerating the rate of filtration. c. deplugging the filter medium. d. enhancing the cake porosity in case of a dense impermeable cake.

Answer 167

c. deplugging the filter medium.

Question 168

In gas absorption, one solute is being absorbed while the rest of the components are assumed to be ______ and the liquid is ________. a. inert, volatile b. non-soluble, non-volatile c. non-soluble, volatile d. soluble, volatile

Answer 168

b. non-soluble, non-volatile

Question 169

In general, operating pressure should be ___ and temperature ___for an absorber, to minimize stage requirements and/or absorbent flow rate to lower the equipment volume required to accommodate the gas flow. a. high, low c. low, high b. maximum, low d. minimum, high

Answer 169

a. high, low

Question 170

In hindered settling, particles are a. placed farther from the wall b. near each other c. not affected by other particles and the wall d. none of these

Answer 170

b. near each other

Question 171

In McCabe-Thiele method of theoretical plate calculation for a distillation column, the operating lines of stripping and rectifying sections coincide with the diagonal at __________ reflux. a. total c. minimum b. operating

Answer 171

a. total

Question 172

In most of the mechanically agitated liquid-liquid extractors, baffles or horizontal compartmental plates are provided, which helps in a. maintaining the concentration difference between the two phases. b. all of these c. reducing the axial mixing. d. increasing the rate of extraction.

Answer 172

b. all of these

Question 173

In most of the vacuum crystallizer, vacuum is generally produced by means of a a. suction pump b. compressed air jet c. steam jet ejector with a barometric condenser d. none of these

Answer 173

c. steam jet ejector with a barometric condenser

Question 174

In operating a batch filter, which of the following is the correct method of operation? a. Keeping the flowrate constant and gradually increase the pressure. b. The particles forming the cake should be large. c. The slower the flowrate, the more efficient the recovery. d. Keeping the pressure constant, the rate of flow increases.

Answer 174

a. Keeping the flowrate constant and gradually increase the pressure.

Question 175

In plug flow tubular reactor the axial velocity profile on cross-section will be a. non-linear b. power function of time c. varying with time d. constant

Answer 175

d. constant

Question 176

In screen analysis, notation 10 mm / 5 mm means passing through a. 10 mm screen and retained on 5 mm screen b. 5 mm screen and retained on 10 mm screen c. both 5 mm and 13 mm screens d. neither 5 mm nor 10 mm screens

Answer 176

a. 10 mm screen and retained on 5 mm screen

Question 177

In steam distillation, the a. temperature is 100°C. b. temperature is more than 100° C. c. product must be immiscible with water.

Answer 177

c. product must be immiscible with water.

Question 178

In thermal radiation, for a black body where α is absorptivity and ε is emissivity. a. α= 1 and ε is not equal to 1 b. α is not equal to 1 and ε= 1 c. α and ε are not equal to 1 d. α= 1 and ε= 1

Answer 178

d. α= 1 and ε= 1

Question 179

In washing type plate and frame filter press, the ratio of washing rate to the final filtrate rate is a. 4 c. 1/4 b. 1 d. 1/2

Answer 179

c. 1/4

Question 180

Increasing the capacity of screen a. decreases the screen effectiveness b. does not affect the screen effectiveness c. increases the screen effectiveness d. none of these

Answer 180

a. decreases the screen effectiveness

Question 181

Increasing the liquor level in the evaporator results in the a. decreased capacity. b. increase in liquor film co-efficient. c. decreased effect of hydrostatic head. d. increased true temperature drop.

Answer 181

a. decreased capacity.

Question 182

Increasing the operating pressure of a distilling column a. does not make a difference in components separation b. makes separation difficult c. sharpens separation

Answer 182

b. makes separation difficult

Question 183

Inside the distillation column, the a. driving force for the vapor flow is the pressure drop. b. liquids are not always at their bubble points. c. pressure increases gradually from bottom to the top of the column.

Answer 183

a. driving force for the vapor flow is the pressure drop.

Question 184

Internal energy change of a system over one complete cycle in a cyclic process is a. zero c. +ve b. -ve d. dependent on the path

Answer 184

a. zero

Question 185

Inversion of cane sugar is an example of a. unimolecular reaction with first order. b. bimolecular reaction with second order. c. bimolecular reaction with first order. d. unimolecular reaction with second order.

Answer 185

c. bimolecular reaction with first order.

Question 186

Isobaric process means a constant a. temperature process c. pressure process b. volume process d. entropy process

Answer 186

c. pressure process

Question 187

It is not preferable to use superheated steam in evaporators, because of its very a. high temperature c. high pressure b. low film coefficient d. none of these

Answer 187

b. low film coefficient

Question 188

It represents the total mass transferred to mass transferred by molecular diffusion. a. Schmidt Number c. Reynolds Number b. Sherwood Number d. Nusselt Number

Answer 188

b. Sherwood Number

Question 189

kg of liquid evaporated per hour in an evaporator is defined as its a. capacity c. economy b. steam load d. none of these

Answer 189

a. capacity

Question 190

Kick's law relates to a. energy consumption c. final particle size b. feed size d. none of these

Answer 190

a. energy consumption

Question 191

Large scale drying of sugar is done in a __________ dryer. a. spouted bed c. tray b. rotary d. truck

Answer 191

b. rotary

Question 192

Large scale usage of flash distillation is practiced in a. ammonia synthesis plant b. polymerization industry c. petroleum refinning d. soap manufacturing

Answer 192

c. petroleum refinning

Question 193

Large scale usage of flash distillation is practiced in a. polymerization industry b. soap manufacturing c. petroleum refinning d. ammonia synthesis plant

Answer 193

c. petroleum refinning

Question 194

Leaching of sugar from sugar beets is done using a. hot water c. dilute H2SO4 b. hexane

Answer 194

a. hot water

Question 195

Leaching of uranium ore and gold ore is done in a. centrifugal extractor c. Pachuka tanks b. Bollman extractor

Answer 195

c. Pachuka tanks

Question 196

Location of vena-contracta in an orificemeter does not depend upon the a. pipe roughness. b. density, viscosity & compressibility of the fluid. c. type of orifice. d. ratio of pipe diameter to orifice diameter.

Answer 196

c. type of orifice.

Question 197

Maximum size reduction in a ball mill is done by a. attrition c. impact b. compression d. cutting

Answer 197

c. impact

Question 198

Maximum work that could be secured by expanding the gas over a given pressure range is the __________ work. a. isothermal c. adiabatic b. isentropic d. none of these

Answer 198

a. isothermal

Question 199

Measurement of thermodynamic property of temperature is facilitated by __________ law of thermodynamics. a. 1st c. zeroth b. 3rd d. none of these

Answer 199

c. zeroth

Question 200

Melting of ice is an example of an __________ process. a. adiabatic c. isothermal b. isometric d. none of these

Answer 200

c. isothermal

Question 201

Melting of wax is accompanied with __________ in entropy. a. increase c. decrease b. no change d. none of these

Answer 201

a. increase

Question 202

Milk is dried usually in a __________ dryer. a. freeze c. spray b. tray d. rotary

Answer 202

c. spray

Question 203

Moisture contained by a substance in excess of the equilibrium moisture is called a. unbound moisture c. free moisture b. critical moisture d. bound moisture

Answer 203

c. free moisture

Question 204

Moisture in a substance exerting an equilibrium vapor pressure less than that of pure liquid at the same temperature is called the __________ moisture. a. bound c. unbound b. critical d. none of these

Answer 204

a. bound

Question 205

Molecular diffusivity of a liquid – a. increases with temperature b. may increase or decrease with temperature c. decreases with temperature d. is independent of temperature

Answer 205

a. increases with temperature

Question 206

Molten soap mass is transported by a        pump. a. gear b. centrifugal c. diaphragm d. reciprocating

Answer 206

b. centrifugal

Question 207

Most commonly used joint in the underground pipe lines is the a. expansion joint b. coupling c. flange d. sleevejoint

Answer 207

d. sleevejoint

Question 208

Multiple effect evaporation is generally recommended, when the a. large scale evaporation of liquor is needed. b. corrosive liquids are to be concentrated. c. fuel is cheaply available. d. evaporation on small scale is to be done.

Answer 208

a. large scale evaporation of liquor is needed.

Question 209

No work is done by the system, when a reaction occurs at constant a. volume c. temperature b. pressure d. none of these

Answer 209

a. volume

Question 210

Nominal size of the discharge pipe of a pump is usually           the nominal size of the inlet pipe. a. twice b. same as c. larger than d. smaller than

Answer 210

d. smaller than

Question 211

One mole feed of a binary mixture of a given composition is flash vaporized at a fixed P and T. If Raoult's law is obeyed, then changing the feed composition would effect a. the product composition but not the fraction vaporized. b. the product composition as well as the fraction vaporized. c. the fraction vaporized but not the product composition.

Answer 211

c. the fraction vaporized but not the product composition.

Question 212

One ton of refrigeration is defined as the heat rate corresponding to melting of one ton of ice in one a. hour c. day b. minute d. second

Answer 212

c. day

Question 213

Operating velocity in a packed tower is usually a. half the flooding velocity b. twice the flooding velocity c. equal to flooding velocity d. more than the flooding velocity

Answer 213

a. half the flooding velocity

Question 214

Overall efficiency of the distillation column is a. the ratio of number of ideal plates to actual plates b. the ratio of number of actual plates to ideal plates c. same as the Murphree efficiency

Answer 214

a. the ratio of number of ideal plates to actual plates

Question 215

Pick out the correct statement a. Reactions with high activation energies are very temperature sensitive. b. A chemical reaction occurs when the energy of the reacting molecule is less than the activation energy of the reaction. c. A photochemical reaction is catalyzed by light. d. Chemical equilibrium is a static state.

Answer 215

a. Reactions with high activation energies are very temperature sensitive.

Question 216

Pick out the correct statement. a. Ponchon-Savarit method is more accurate than McCabe-Thiele method to determine the number of theoretical stages required for the separation of non-ideal binary system by distillation. b. A sharp decrease in pressure drop is an indication of flooding in a distillation column. c. Solvent used in extractive distillation should be of high volatility.

Answer 216

a. Ponchon-Savarit method is more accurate than McCabe-Thiele method to determine the number of theoretical stages required for the separation of non-ideal binary system by distillation.

Question 217

Pick out the system with minimum boiling azeotrope at 1 atm. a. benzene-toluene c. hydrochloric acid-water b. ethyl alcohol-water

Answer 217

b. ethyl alcohol-water

Question 218

Pick out the wrong statement pertaining to space velocity of flow reactors. a. none of these. b. The space velocity of 3 / hr means that one third reactor volume of feed at specified conditions are being fed into the reactor. c. The space velocity of 3 / hr means that three reactor volumes of feed at specified conditions are being fed into the reactor every hour. d. The unit of space velocity is (per time) .

Answer 218

b. The space velocity of 3 / hr means that one third reactor volume of feed at specified conditions are being fed into the reactor.

Question 219

Pick out the wrong statement pertaining to the rotary dryer. a. Flights (located in the inside shell of rotary dryer) lift the material being dried and shower it down through the current of hot air/gases. It extends from the wall to a distance which is about 8-12% of the inside diameter of shell. b. Hold up of a rotary drier is defined as the fraction of the dryer volume occupied by the solid at any instant. The best performance for rotary drier is obtained, when the holdup is in the range of 0.05 to 0.15. c. Rotary dryer is suitable for drying sticky material. d. Recommended peripherial speed of a rotary drier is in the range of 10 to 30 meters/minute.

Answer 219

c. Rotary dryer is suitable for drying sticky material.

Question 220

Pick out the wrong statement. a. Critical moisture content is not a property of the material itself. b. A sharp increase in pressure drop gives an indication of the flooding in a distillation column. c. Separation of components is not possible in liquid extraction, if selectivity is unity.

Answer 220

d. Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum.

Question 221

Pick out the wrong statement. a. The mole fraction of solute is directly proportional to the molality of a 'dilute' solution. b. For a non-reacting binary mixture of ideal gases, the partial pressure distribution of both components is nonlinear in the case of steady state unimolal unidirectional diffusion. c. Azeotropes obey Raoult's law at all temperature.

Answer 221

c. Azeotropes obey Raoult's law at all temperature.

Question 222

Pick out the wrong statement. a. Hammer crushers operate by impact action. b. Standard screens have circular opening. c. With increase in mesh number of screens, their diameter in microns decreases. d. 200 mesh screen has 200 openings per linear cm.

Answer 222

d. 200 mesh screen has 200 openings per linear cm.

Question 223

Pick out the wrong statement. a. The controlling resistance in case of heating of air by condensing steam is in the air film. b. Phase change in case of a pure fluid at a given pressure from liquid to vapor or vice-versa occurs at saturation temperature. c. In case of a 1 - 2 shell and tube heat exchanger, the LMTD correction factor value increases sharply, when a temperature cross occurs. d. The log mean temperature difference (LMTD) for counter flow and parallel flow can be theoretically same when any one of the fluids (hot or cold fluid) passes through the heat exchanger at constant temperature.

Answer 223

c. In case of a 1 - 2 shell and tube heat exchanger, the LMTD correction factor value increases sharply, when a temperature cross occurs.

Question 224

Pipes having diameter 14 inches or more are designated by their a. schedule number b. cross-sectional area c. outside diameter d. inside diameter

Answer 224

c. outside diameter

Question 225

Ponchan-Savarit method analyses the fractional equipment based on a. enthalpy balance only. b. material balance only. c. both enthalpy and material balances.

Answer 225

c. both enthalpy and material balances.

Question 226

Positive deviation from Raoult's law means a mixture whose total pressure is a. greater than that computed for ideality. b. less than that computed for ideality. c. less than the sum of the vapour pressure of the components.

Answer 226

a. greater than that computed for ideality.

Question 227

Power required to drive a ball mill with a particular ball load is proportional to (where, D = diameter of ball mill ) a. D c. 1/D b. D2.5 d. 1/D2.5

Answer 227

b. D2.5

Question 228

Pulverized coal passing through 200-mesh screen has a diameter of 0.074 mm (74 micron). The same passing through 50-mesh screen will have a diameter of __________ mm. a. 0.007 c. 0.30 b. 50 d. 0.014

Answer 228

c. 0.30

Question 229

Radioactive nuclear waste is treated in a. mixer-settler extractor b. rotating-disc contactor c. pulsed column extractor

Answer 229

c. pulsed column extractor

Question 230

Rate of leaching increases with increasing a. temperature c. viscosity of solvent b. pressure

Answer 230

a. temperature

Question 231

Reciprocal of sphericity is termed as the a. specific surface ratio c. shape factor b. Sauter diameter d. surface area per unit mass

Answer 231

c. shape factor

Question 232

Relative volatility varies with the concentration of component for an ideal solution. The relative volatility of a binary mixture may be defined as the ratio of vapor pressure of component 'A' to that of component 'B', when a. only vapor phase follows Raoult's law. b. only liquid phase obeys Dalton's law. c. liquid phase obeys Dalton's law and vapor phase obeys Raoult's law.

Answer 232

d. Vapor phase obeys Dalton's law and liquid phase obeys Raoult's law.

Question 233

Schedule number of a pipe, which is a measure of its wall thickness, is given by a. 1000 P'/S b. 100 P'/S c. 10000 P'/S d. 1000 S/P'

Answer 233

a. 1000 P'/S

Question 234

Screen capacity is not a function of a. its openings size c. screening mechanism b. screening surface d. atmospheric humidity

Answer 234

d. atmospheric humidity

Question 235

Screen efficiency is a. recovery/rejection c. recovery b. rejection d. none of these

Answer 235

a. recovery/rejection

Question 236

Separation of a mixture of two gases by absorption in the liquid solvent depends upon the difference in their a. viscosity c. density b. solubility d. relative volatility

Answer 236

b. solubility

Question 237

Separation of two or more components of a liquid solution cannot be achieved by a. liquid extraction c. fractional crystallization b. absorption

Answer 237

b. absorption

Question 238

Shell side pressure drop in a shell and tube heat exchanger does not depend upon the a. none of these. b. viscosity, density & mass velocity of shell side fluid. c. baffle spacing & shell diameter. d. tube diameter & pitch.

Answer 238

a. none of these.

Question 239

Size measurement of ultrafine particles can be best expressed in terms of a. centimeters c. screen size b. micron d. surface area/unit mass

Answer 239

d. surface area/unit mass

Question 240

Size reduction does not occur due to compression in case of a. rod mills c. gyratory crushers b. jaw crushers d. smooth roll crushers

Answer 240

a. rod mills

Question 241

Size reduction of asbestos and mica is done by a. hammer mills c. rod mills b. gyratory crushers d. crushing rolls

Answer 241

a. hammer mills

Question 242

Small scale evaporation is done in a a. heat exchange b. multiple effect evaporator c. condenser d. steam jacketed kettle

Answer 242

d. steam jacketed kettle

Question 243

Smoker's equation for the calculation of number of equilibrium stages in a continuous binary distillation column is used, when the a. relative volatility is close to one (e.g., separation of close boiling isomers). b. feed is not at its bubble point. c. number of equilibrium stages in only stripping section is to be calculated.

Answer 243

a. relative volatility is close to one (e.g., separation of close boiling isomers).

Question 244

Solvent extraction is the terminology applied to the liquid-liquid extraction, which is preferred for the separation of the components of liquids, when a. extracting solvent is cheaply and abundantly available. c. viscosity of liquid components is very high. b. one of the liquid components is heat sensitive.

Answer 244

d. one of the liquid components has very high affinity towards the solvent.

Question 245

Solvent used in extractive distillation a. does not alter the relative volatility of the original component b. forms a high boiling azeotrope. c. is of low volatility. d. forms a low boiling azeotrope.

Answer 245

d. forms a low boiling azeotrope.

Question 246

Sphericity for a cylinder whose length equals its diameter a. 1.5 c. 0.87 b. 0.5 d. 0.73

Answer 246

c. 0.87

Question 247

Sphericity of Raschig ring (whose length and diameter are equal) is a. >1 c. <1 b. 1 d. 2

Answer 247

b. 1

Question 248

Steady state temperature reached by a small amount of liquid evaporating into a large amount of unsaturated vapor-gas mixture is a. dry-bulb temperature b. wet bulb temperature c. dew point d. adiabatic saturation temperature

Answer 248

b. wet bulb temperature

Question 249

Steam distillation is used to a. reduce the number of plates. b. avoid thermal decomposition of a component. c. increase the efficiency of separation.

Answer 249

b. avoid thermal decomposition of a component.

Question 250

Stoke’s law is valid when the particle Reynolds number is a. <1 c. >1 b. <5 d. none of these

Answer 250

a. <1

Question 251

Tea percolation employs a. solvent extraction c. absorption b. leaching

Answer 251

b. leaching

Question 252

Terminal velocity is a. constant velocity with no acceleration b. a fluctuating velocity c. attained after moving one-half of total distance d. none of these

Answer 252

a. constant velocity with no acceleration

Question 253

The amount of heat absorbed when CO2 gas reacts with a solid CaO to form solid CaCO3 is measured in a bomb calorimeter at constant volume. The data obtained give a direct measure of a. △U c. △H b. V△P d. Cp

Answer 253

a. △U

Question 254

The apex of an equilateral-triangular coordinate (in ternary liquid system) represents a/an b. repeated small washing c. binary mixture b. ternary mixture

Answer 254

b. repeated small washing

Question 255

The assumption made in Elis method in distillation is that enthalpy concentration lines of vapor and liquid are a. parallel b. straight c. both parallel and straight

Answer 255

c. both parallel and straight

Question 256

The commonly used solvent in supercritical extraction is a. methyl ethyl ketone c. water b. carbon tetrachloride

Answer 256

d. carbon dioxide

Question 257

The concentration of A in a first order reaction, A → B, decreases a. linearly with time. b. exponentially with time. c. very abruptly towards the end of the reaction. d. logarithmically with time.

Answer 257

b. exponentially with time.

Question 258

The dimensionless group in mass transfer that is equivalent to Prandtl number in heat transfer is a. Stanton number. b. Schmidt number. c. Nusselt number d. Sherwood number

Answer 258

b. Schmidt number.

Question 259

The dimensionless number that characterizes the flows of fluid in a conduit. a. Nusselt number c. Grashof number b. Peclet number d. Reynolds number

Answer 259

d. Reynolds number

Question 260

The driving force in heat transfer is a. concentration gradient c. viscosity gradient b. temperature gradient d. thickness of the solid in question

Answer 260

b. temperature gradient

Question 261

The driving potential for the crystal growth during crystallization is the __________ of the solution. a. concentration c. viscosity b. super-saturation d. density

Answer 261

b. super-saturation

Question 262

The ease of difficulty of separating components by distillation is determined by the a. relative volatility c. mole fraction b. viscosity

Answer 262

a. relative volatility

Question 263

The efficiency of Carnot cycle is ___ the efficiency of Rankine cycle. a. less than c. equal to b. greater than d. less than or greater than

Answer 263

b. greater than

Question 264

The enrichment of ethyl alcohol in the vapor phase from an aqueous ethyl alcohol solution during rectification is an example of a. unicomponent diffusion b. equimolal counterdiffusion c. phase drift d. convective diffusion

Answer 264

b. equimolal counterdiffusion

Question 265

The equation, PV = nRT is best obeyed by gases at a. low pressure and high temperature b. high pressure and low temperature c. low pressure and low temperature d. none of these

Answer 265

a. low pressure and high temperature

Question 266

The equilibrium constant of a chemical reaction a. increases in the presence of catalyst b. decreases in the presence of catalyst c. remains unaffected in the presence of a catalyst d. can either increase or decrease; depends on the type of catalyst

Answer 266

c. remains unaffected in the presence of a catalyst

Question 267

The equilibrium liquid composition compared to the vapor composition in case of azeotropic mixture is a. more b. less c. same

Answer 267

c. same

Question 268

The equipment used in the extraction of highly corrosive radioactive liquids is a. pulse column c. spray column b. mixer settler

Answer 268

a. pulse column

Question 269

The expression for the work done for a reversible polytropic process can be used to obtain the expression for work done for all processes, except reversible __________ process. a. isobaric c. isothermal b. adiabatic d. none of these

Answer 269

c. isothermal

Question 270

The Fick’s Law of Diffusion gives the rate of diffusion based on a. pressure driving force b. temperature driving force c. concentration driving force d. all of these

Answer 270

c. concentration driving force

Question 271

The fixed cost of a distillation column at minimum reflux ratio is a. None of these b. minimum c. optimum d. infinite

Answer 271

d. infinite

Question 272

The half-life of a material undergoing second order decay is a. proportional to the square of initial concentration b. independent of initial concentration c. proportional to initial concentration d. inversely proportional to initial concentration

Answer 272

d. inversely proportional to initial concentration

Question 273

The insulation ability of an insulator with the presence of moisture would a. increase c. remains unaffected b. decrease d. none of the above

Answer 273

b. decrease

Question 274

The material is crushed in a gyratory crusher by the action of a. impact c. compression b. attrition d. cutting

Answer 274

c. compression

Question 275

The most suitable equipment for the transportation of 200 mesh size particles is a a. bucket elevator c. pneumatic conveyor b. screw conveyor d. belt conveyor

Answer 275

c. pneumatic conveyor

Question 276

The number of kg vaporized per kg of steam fed to the evaporator is defined as a. capacity c. rate of evaporation b. economy d. rate of vaporization

Answer 276

b. economy

Question 277

The opening of a 200-mesh screen (Tyler series) is a. 0.0074 cm c. 0.0074 mm b. 0.0047 cm d. 74 millimicrons

Answer 277

a. 0.0074 cm

Question 278

The operating speed of a ball mill should be a. less than the critical speed b. at least equal to the critical speed c. much more than the critical speed d. none of these

Answer 278

a. less than the critical speed

Question 279

The operation by which solids are separated from liquids due to difference in the respective densities is a. screening c. sedimentation b. adsorption d. absorption

Answer 279

c. sedimentation

Question 280

The operation involved when the soluble material is largely on the surface of an insoluble solid and is merely washed off by the solvent is called a. percolation b. elutriation or elution c. none of these d. decoction

Answer 280

b. elutriation or elution

Question 281

The optimum moisture content in solids to be crushed/ground ranges from __________ percent. a. 3 to 4 c. 8 to 10 b. 10 to 15 d. 15 to 20

Answer 281

a. 3 to 4

Question 282

The physical separation of components in a miscible mixture by simultaneous evaporation and condensation is a. absorption c. extraction b. drying

Answer 282

d. distillation

Question 283

The porosity of a compressible cake is a. minimum at the filter medium b. minimum at the upstream face c. maximum at the filter medium d. same throughout the thickness

Answer 283

a. minimum at the filter medium

Question 284

The rate at which a chemical substance reacts is proportional to its a. atomic weight b. equivalent weight c. molecular weight d.active mass

Answer 284

d.active mass

Question 285

The rate constant of a chemical reaction decreases by decreasing the a. concentration of reactants b. pressure c. temperature d. duration of reaction

Answer 285

c. temperature

Question 286

The rate of heat transfer is a product of overall heat transfer co-efficient, the difference in temperature and the a. heating volume c. heat transfer area b. Nusselt number d. none of these

Answer 286

c. heat transfer area

Question 287

The rate of the reaction, X → Y, quadruples when the concentration of 'X' is doubled. The rate expression for the reaction is, -r = k Cxn, the value of 'n' in this case will be a. 0 c. 1 b. 2 d. 3

Answer 287

b. 2

Question 288

The ratio of volume of mixed reactor to the volume of P.F.R. (for identical flow rate, feed composition and conversion) for zero order reaction is a. 1 b. ∞ c. >1 d. 0

Answer 288

a. 1

Question 289

The reaction in which rate equation corresponds to a stoichiometric equation is called a. elementary reaction c. non-elementary reaction b. parallel reaction d. autocatalytic reaction

Answer 289

a. elementary reaction

Question 290

The reaction A (l)  R(g) is allowed to reach equilibrium conditions in an autoclave. At equilibrium, there are two phases, one a pure liquid phase of A and the other a vapor phase of A, R and S. Initially A alone is present. The number of degrees of freedom are a. 1 b. 3 c. 0 d. 2

Answer 290

d. 2

Question 291

The relative volatility of a binary mixture at the azeotropic composition is a. 1 c. > 1 b. 0

Answer 291

a. 1

Question 292

The reverse is true for stripping. However, the operating pressure should not be too high and the operating temperature should not be too low as to ___ the feed gas. a. vaporize c. condense b. compress d. none of these

Answer 292

c. condense

Question 293

The shape of T-S diagram for Carnot Cycle is a a. rectangle c. rhombus b. trapezoid d. circle

Answer 293

a. rectangle

Question 294

The solvent used in liquid extraction should not have high latent heat of vaporization, because a. the pressure drop and hence the pumping cost will be very high. c. its recovery cost by distillation may be prohibitively high. b. it cannot be recovered by distillation.

Answer 294

c. its recovery cost by distillation may be prohibitively high.

Question 295

The terminal velocity of a small sphere settling in a viscous fluid varies as the a. first power of its diameter b. inverse of the fluid viscosity c. inverse square of the diameter d. square of the difference in specific weights of solid and fluid

Answer 295

b. inverse of the fluid viscosity

Question 296

The unit of filter medium resistance is a. cm-1 c. gm/cm-1 b. cm/gm-1 d. gm-1

Answer 296

a. cm-1

Question 297

The unit of specific cake resistance is a. gm/cm2 c. cm/gm B. cm/gm2 d. gm/gm

Answer 297

a. gm/cm2

Question 298

The viscosity of a gas a. decreases with increase in temperature b. increases with increase in temperature c. is independent of temperature d. is independent of pressure for very high pressure intensities

Answer 298

b. increases with increase in temperature

Question 299

The-relative volatility for separation of a non-ideal binary mixture by distillation should be a. 0 c. 1 b. > 1

Answer 299

b. > 1

Question 300

Thermal diffusivity of a material a. has the unit m2 /sec. b. is defined as k/ρ x Cp. c. is the ratio of thermal conductivity to thermal capacity. d. all (a), (b) and (c).

Answer 300

d. all (a), (b) and (c).

Question 301

This dimensionless number relates buoyancy forces to viscous forces. a. Archimedes Number b. Rayleigh Number c. Graetz Number d. Grashof Number

Answer 301

d. Grashof Number

Question 302

To get high tray efficiency a. gas velocity should be very low. b. interfacial surface between liquid and gas phase should be large. c. liquid entrainment should be severe. d. time of contact between the two phases should be less.

Answer 302

b. interfacial surface between liquid and gas phase should be large.

Question 303

To get ultrafine particles, the equipment used is a. ball mill c. hammer crusher b. rod mill d. fluid energy mill

Answer 303

d. fluid energy mill

Question 304

Traces of solids are removed from, liquid in a a. classifier c. clarifier b. sparkler filter d. rotary vacuum filter

Answer 304

c. clarifier

Question 305

Tray spacing in a distillation column of dia 10-12 ft. used in petroleum refinery may be around __________ inches. a. 30 b. 5 c. 60 d. 100

Answer 305

a. 30

Question 306

Trommels separate a mixture of particles depending on their a. electrical and magnetic properties b. size c. wettability d. density

Answer 306

b. size

Question 307

Turbulent flow generally occurs for cases involving a. viscous fluid b. very narrow passages for capillary tube c. very slow motions d. none of these

Answer 307

d. none of these

Question 308

Ultra centrifuges are used for the separation of _____ solid particles. a. coarse c. fine b. colloidal d. dissolved

Answer 308

b. colloidal

Question 309

Ultracentrifuges running at speeds up to 100000 rpm is normally used for the a. separation of isotopes based on their density or molecular weights difference. b. concentration of rubber latex. c. separation of cream from milk. d. dewaxing of lubricating oil.

Answer 309

a. separation of isotopes based on their density or molecular weights difference.

Question 310

Under the same temperature gradient across various metal plates of the same thickness, the heat conducted per unit of surface area will be largest across a. lead c. iron b. copper d. nickel

Answer 310

b. copper

Question 311

Viscous and heat sensitive liquids are concentrated in __________ evaporators. a. open pan c. long tube b. agitated film d. none of these

Answer 311

b. agitated film

Question 312

Water hammer in a pipeline results from the a. pressure increase due to closure of a valve resulting in decrease in rate of flow. b. none of these c. bursting of pipelines due to closure by a valve. d. rapid pressure change due to a rapid change in the rate of flow.

Answer 312

d. rapid pressure change due to a rapid change in the rate of flow.

Question 313

Weight of 1 m3 of humid air as compared to 1 m3 of dry air, under the same conditions, is a. less c. more b. same d. unpredictable

Answer 313

a. less

Question 314

What could be the effect of lowering the temperature of stripping? a. number of stages increases b. number of stages decreases c. either a or b d. cannot be determined

Answer 314

a. number of stages increases

Question 315

What happens to delta U when work is done by the system during the adiabatic expansion of ideal gas? a. no change b. zero c. increases d. decreases

Answer 315

d. decreases

Question 316

What is the dispersion number for a CSTR? a. 0 b. 1 c. ∞ d. <1

Answer 316

c. ∞

Question 317

What is the reflux ratio at total reflux ? a. zero b. unity c. infinity d. data insufficient

Answer 317

c. infinity

Question 318

What is the steam economy in case of a single effect evaporator system? a. 1 c. >1 b. < 1 d. 0.1

Answer 318

b. < 1

Question 319

What is the unit of the rate constant in a chemical reaction in which 10% of the reactant decomposes in one hour, 20% in two hours, 30% in three hours and so on? a. Liter/mole b. Liter/mole-second c. Liter/mole-second d. liter/secod

Answer 319

c. Liter/mole-second

Question 320

When a fluid flows through a reducer in a piping system, the velocity at the outlet end is _ the velocity at the inlet. a. less than c. the same as b. more than d. one-half

Answer 320

b. more than

Question 321

When an unsaturated air-water mixture is heated at constant pressure, then a. the partial pressure of water vapor increases. b. the specific humidity decreases. c. the relative humidity increases. d. the relative humidity decreases.

Answer 321

d. the relative humidity decreases.

Question 322

When heat is transferred from hot body to cold body, in a straight line, without affecting the intervening medium, it is referred as heat transfer by a. conduction c. radiation b. convection d. convection and radiation

Answer 322

c. radiation

Question 323

When the feed to a distillation column is a saturated liquid, slope of the feed line is a. zero c. unity b. infinity

Answer 323

b. infinity

Question 324

When the flow is laminar a. the pressure drop is inversely proportional to the velocity. b. the pressure drop is not affected by the velocity. c. the pressure drop is proportional to the first power of the velocity d. the pressure drop is proportional to the square of the velocity

Answer 324

c. the pressure drop is proportional to the first power of the velocity

Question 325

When the liquid phase and vapor phase of a binary system obeys Raoult's and Dalton's law respectively, the relative volatility is the ratio of a. vapor pressure of component A to that of component B. b. vapor pressure of component A to the total pressure. c. vapor pressure of component A to the partial pressure of A.

Answer 325

a. vapor pressure of component A to that of component B.

Question 326

When the mixture to be distilled has a very high boiling point and the product material is heat sensitive, the separation technique to be used is __________ distillation. a. continuous c. steam b. azeotropic

Answer 326

c. steam

Question 327

When the solvent dissolves very little of solute, then a. solvent of low latent heat of vaporization should be used. c. large quantity of solvent is required to extract the solute. b. solvent of low freezing point should be used.

Answer 327

c. large quantity of solvent is required to extract the solute.

Question 328

When the temperature and humidity of air is low, we usually use __________ draft cooling tower. a. natural c. forced b. induced d. none of these

Answer 328

a. natural

Question 329

Where the density difference of the two liquid phase to be separated is very small (as in milk cream separator), the most suitable separator is a a. disc bowl centrifuge b. batch basket centrifuge c. sharpies super centrifuge d. sparkler filter

Answer 329

a. disc bowl centrifuge

Question 330

Which is the most suitable for the concentration of foamy and frothy liquors? a. Agitated film evaporator b. Long tube vertical evaporator c. Open pan evaporator d. None of these

Answer 330

b. Long tube vertical evaporator

Question 331

Which method is more efficient, a single large washing or repeated small washing? a. single large washing c. either single large or repeated small washing b. repeated small washing

Answer 331

b. repeated small washing

Question 332

Which of the following accessories is provided in the vapor line of an evaporator for removing the entrained liquid? a. Bleed point c. Vent b. Catchall d. Baffle

Answer 332

b. Catchall

Question 333

Which of the following applies to a feed at dew point? a. f=0 b. 01 d. f=1

Answer 333

d. f=1

Question 334

Which of the following binary systems is an example of a maximum boiling azeotrope? a. water-hydrochloric acid b. acetone-carbon disulfide c. water-ethyl alcohol

Answer 334

a. water-hydrochloric acid

Question 335

Which of the following equipment is not used for liquid dispersion? a. Wetted wall towers c. Venturi scrubbers b. Packed tower

Answer 335

b. Packed tower

Question 336

Which of the following equipment is not used in liquid-liquid extraction? a. Pachuka tank c. Agitated vessels b. Packed towers

Answer 336

a. Pachuka tank

Question 337

Which of the following gives the crushing energy required to create new surface? a. Taggarts rule c. Fick's law b. Rittinger's law d. none of these

Answer 337

b. Rittinger's law

Question 338

Which of the following has the least thermal efficiency? a. Steam engine c. Carnot engine b. Diesel engine d. Otto engine

Answer 338

a. Steam engine

Question 339

Which of the following is a vacuum filter? a. Tank filter (Nutsch filter) b. Rotary disc filter c. Filter press d. Batch basket centrifuge

Answer 339

b. Rotary disc filter

Question 340

Which of the following is a vacuum filter? a.Filter press b. Rotary disc filter c. Batch basket centrifuge d. Tank filter (Nutsch filter)

Answer 340

b. Rotary disc filter

Question 341

Which of the following is an example of a hard material? a. talc c. sapphire b. calcite d. feldspar

Answer 341

c. sapphire

Question 342

Which of the following is an undesirable property for an absorbing solvent? a. Low vapor pressure c. Low viscosity b. Low freezing point

Answer 342

d. None of these

Question 343

Which of the following is not a continuous drier? a. Drum drier c. Spray drier b. Tunnel drier d. Tray drier

Answer 343

d. Tray drier

Question 344

Which of the following is not a continuous leaching equipment? a. Pachuka tank b. Hydrocyclones c. Bollman extractor d. Kennedy extractor

Answer 344

a. Pachuka tank

Question 345

Which of the following is not true? a. A pump will operate safely if its NPSH is greater than zero. b. Fans and blowers are used to transport gases. c. Pumps and blowers increase the mechanical energy of the fluid. d. The power loss due to friction in a venturi meter is greater than in an orifice meter.

Answer 345

d. The power loss due to friction in a venturi meter is greater than in an orifice meter.

Question 346

Which of the following is not used as filter aid? a. Asbestos b. Diatomaceous earth c. Purified wood cellulose d. Rice husk

Answer 346

d. Rice husk

Question 347

Which of the following is the most commonly used leaching solvent in vegetable oil industry? a. phenol c. furfural b. hexane

Answer 347

b. hexane

Question 348

Which of the following is the most suitable for extraction in a system having very low-density difference? a. Mixer-settler extractor b. Centrifugal extractor c. Pulsed extractor

Answer 348

b. Centrifugal extractor

Question 349

Which of the following is the most suitable for very high pressure gas phase reaction ? a. batch reactor b. Stirred tank reactor c. Fluidised bed reactor d. Tubular flow reactor

Answer 349

d. Tubular flow reactor

Question 350

Which of the following is the softest material? a. talc c. feldspar b. corundum d. calcite

Answer 350

a. talc

Question 351

Which of the following is true about rate of mass transfer in liquid? a. NA = kG (Pab – Pai) c. NA = kC (Pab – Pai) b. NA = kG (Cab – Cai) d. NA = kC (Cab – Cai)

Answer 351

d. NA = kC (Cab – Cai)

Question 352

Which of the following liquid-vapor contacting devices provides maximum contact surface area for a particular duty ? a. Wetted wall column b. Bubble cap column c. Randomly packed column d. Sieve plate column

Answer 352

a. Wetted wall column

Question 353

Which of the following mixtures does not form an azeotrope at atmosheric pressure? a. Water-alcohol b. Methyl alcohol-acetone c. none of these d. Butyl acetate-water

Answer 353

c. none of these

Question 354

Which of the following operations does not involve leaching? a. Dissolving gold from ores. c. Dissolving sugar from the cells of the beet. b. Dissolving pharmaceutical products from bark or roots.

Answer 354

d. Removing nicotine from its water solution by kerosene.

Question 355

Which of the following remains constant during evaporative cooling process with recirculated water supply? a. Relative humidity c. Partial pressure of vapor b. Wet bulb temperature d. None of these

Answer 355

b. Wet bulb temperature

Question 356

Which of the following represents the plot of filtrate volume versus time for constant pressure filtration? a. Parabola c. Straight line b. Hyperbola d. Exponential curve

Answer 356

a. Parabola

Question 357

Which of the following solutions will follow Raoult's law most closely? a. A solution of benzene, toluene and o-xylene b. 35% solution of camphor in water c. 35% solution of NH3 in water

Answer 357

a. A solution of benzene, toluene and o-xylene

Question 358

Which of the following unit operations makes use of Thiele-Geddes equation? a. Liquid-liquid extraction b. Solid-liquid extraction c. Multicomponent absorption with chemical reaction

Answer 358

d. Multicomponent distillation.

Question 359

Which of the statements is wrong? a. From Arrhenius Law, the value of the frequency factor, ko does affect the temperature sensitivity. b. Reactions with high E are very T- sensitive, with low E are relatively T – insensitive c. Any given reaction is much more T- sensitive at a low T than at a high T. d. From Arrhenius law, a plot of ln k vs 1/T gives a straight line, with large slope for large E and small slope for small E. \

Answer 359

a. From Arrhenius Law, the value of the frequency factor, ko does affect the temperature sensitivity.

Question 360

Which statement is not true? a. Potential flow is a flow of compressible fluids with no shear. b. Rotameters are variable-head meters. c. There are 8 schedule numbers in used for standard pipes. d. Roughness has no appreciable effect on the friction factor when flow is laminar.

Answer 360

c. There are 8 schedule numbers in used for standard pipes.

Question 361

Which valve is used accurately to regulate the flow of liquids and gases at low flow rates? a. needle valve c. ball valve b. check valve d. globe valve

Answer 361

a. needle valve

Question 362

With decrease in the throughput (compared with the design capacity) for a bubble cap distillation column, its efficiency a. remains same b. may increase or decrease ; depends on individual design c. decreases d. increases

Answer 362

d. increases

Question 363

With increase in compression ratio, the efficiency of the otto engine a. increases c. decreases b. remains constant d. increases linearly

Answer 363

a. increases

Question 364

With increase in initial concentration, the fractional conversion of a first order reaction in each given time a. increases c. decreases b. remains constant d. unpredictable

Answer 364

b. remains constant

Question 365

With increase in temperature, the rate of leaching increases, because the a. thermal conductivity of solute increases. b. none of these c. diffusivity of solute increases. d. viscosity of solvent decreases.

Answer 365

c. diffusivity of solute increases.

Question 366

With increase in temperature, the thermal conductivity of non-metallic amorphous solids a. decreases b. increases c. first decreases up to certain temperature and then increases d. remains constant

Answer 366

b. increases

Question 367

With increase in the pressure drop across the cake, the specific cake resistance for the compressible sludge a. increases c. decreases b. remains constant d. increases linearly

Answer 367

a. increases

Question 368

With increases in temperature, the rate constant obeying Arrhenius equation a. increases b. decreases c. decreases exponentially with temperature d. can either increase or decrease, depends on the frequency factor

Answer 368

a. increases